B4X

Send a Staged Multipart REST Request

Demonstrates Rest.SendReqMultipart, which sends a multipart request using the parts configured on the object, then reads the response in separate steps.

Background. The staged request model separates sending from reading: a SendReq method transmits the request, ReadResponseHeader reads the status line and headers, and a ReadResp method reads the body. This gives fine control over large or streamed messages compared with the single-call full-request methods.

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Dim success As Boolean = False

Dim rest As ChilkatRest
rest.Initialize("rest")
Dim bTls As Boolean = True
Dim bAutoReconnect As Boolean = True
success = rest.Connect("example.com", 443, bTls, bAutoReconnect)
If success = False Then
    Log(rest.LastErrorText)
    Return
End If


'  Configure one multipart part before sending.
rest.PartSelector = "1"
rest.AddHeader("Content-Type", "text/plain")
rest.AddHeader("Content-Disposition", "form-data; name=" & Chr(34) & "field1" & Chr(34))
success = rest.SetMultipartBodyString("value1")
If success = False Then
    Log(rest.LastErrorText)
    Return
End If


'  Send the multipart request using the configured parts.
success = rest.SendReqMultipart("POST", "/api/upload")
If success = False Then
    Log(rest.LastErrorText)
    Return
End If


'  After sending, read the response status line and header fields.  The return value is the HTTP
'  status code, or -1 if no response was received.
Dim statusCode As Int = rest.ReadResponseHeader
If statusCode < 0 Then
    Log(rest.LastErrorText)
    Return
End If

Log("Response status code: " & statusCode)

'  Read the response body as text.
Dim responseBody As String = rest.ReadRespBodyString
If rest.LastMethodSuccess = False Then
    Log(rest.LastErrorText)
    Return
End If

Log(responseBody)